After nearly a quarter-century of making music that's politically and artistically challenging, U2 gets tamed by middle age.

Nine studio albums and 22 years into one of the most protean careers in rock, U2 seems stuck in the aesthetic equivalent of a blind alley. They began their career waving the flag (sometimes literally) for passionate political rock, then traded their earnestness for irony to reinvent themselves as self-aware stars who stopped contemplating "three chords and the truth" to slither to techno's rhythms. On their 1997 PopMart tour, held under a McDonald's-style arch instead of a blood-red sky, they undercut the conventions of rock's stadium spectaculars so thoroughly they had trouble selling seats by the time they were through.

Now they're going back to making smart, airy rock with a song on their lips, that signature sense of inchoate longing in their hearts, and a sense of humor once again absent from their heads. From the accusing child's stare of War to the speed-of-life collage on Achtung Baby, it's always been easy to judge a U2 album by its cover, and with its elegiac black-and-white Anton Corbijn photo of the band, All That You Can't Leave Behind (Interscope) screams earnestness. And for good reason: It's full of anthemic songs with echoing guitar, catchy choruses, and the kind of spacious production Daniel Lanois and Brian Eno also brought to The Joshua Tree. For the most part, the last few albums' worth of disassociated lyrics and daring electronic experimentation all fell under the category of what could be left behind. Somewhere along the way, U2 also left much of the manic joie de vivre they finally found on Achtung Baby.

Of course, U2 were making great albums long before they let themselves have any fun at all, and All That You Can't Leave Behind offers its share of less obvious rewards. It's a simpler songwriter's album from a band that sounds like it has lost faith in anything fancier. On "Stuck in a Moment You Can't Get Out Of," Bono sings, "I'm just trying to find a decent melody" with the same searching regret he once brought to bigger issues; freed from a need to make conceptual or political statements, he finds several tunes -- "Stuck," "Kite," "Walk On" -- as strong as any the band has ever written.

Though they've ostensibly retreated from the techno-infused music of Pop, many of the new songs are also fleshed out by electronic effects -- the warm ambient sounds that begin "Beautiful Day," the buzzing on "Elevation," the soft beats behind "New York." The most striking departure on this album is the band's born-again naïveté. It's one thing to come straight out of Dublin thinking you can change the world -- quite another to just hang up your Fly costume, go back to writing songs like "Peace on Earth," and decide you'd rather be taken at face value, thank you very much.

In the end, the most honest song on the album is "Kite," a quiet meditation on growth, change, and the hard truth that everything ends. It's one of the few places where U2 seem to shake loose from the pressures of trends and the weight of their own history and take a good look at themselves -- "The last of the rock stars / When hip-hop drove the big cars / At a time when new media / Was the big idea." Which wouldn't be such a bad place to be if they hadn't worked so hard to evolve into something more interesting.

When U2 traded in their rock-star attitude for studied sincerity, they may have made the swap with PJ Harvey, who sounds less sex-obsessed than actually sexy on Stories From the City, Stories From the Sea (Island). Instead of theorizing, um, dryly about pleasure, as she did on her 1995 meta-blues masterpiece To Bring You My Love, Harvey sounds like she's actually enjoying herself. The album was mostly written in and inspired by the six months Harvey spent in New York last year, but like most tourists and artists, she writes less about the New York of reality than the New York of the mind -- Martin Scorsese's mind, to be exact. She strolls through downtown with a lover on "Good Fortune," pondering punk possibility with the caged emotion of Patti Smith ("In Chinatown / Hung over / You showed me just what I could do"), sits "on a rooftop in Brooklyn / At one in the morning / Watching the bright lights in Manhattan" with the attitude of Tony Manero, and watches "the whores hustle and the hustlers whore" with the detached contempt of Travis Bickle.

Also like most tourists and artists, she comes out surer of who she is -- and, more important, what she wants. The title of her last album asked Is This Desire? with a temerity Harvey never seemed to have in her. On Stories, "This Is Love" offers a more confident statement, with lyrics -- "I can't believe life is so complex / When I just want to sit here and watch you undress" -- that convey a New York attitude all her own.